Abstract Childhood obesity is a major public health crisis in the United States, affecting 16.9% of youth aged 2-19 and 20.5% of youth aged 12-19. While current family-based interventions are effective in reducing body mass index (BMI) in adolescents; the majority of adolescents regain their excess weight within 2 years. In addition, there is a high rate of drop out from weight management programs, with 27% to 73% of families not completing the full treatment protocol. One possible mechanism influencing pediatric weight management outcomes is chronic pain. Although chronic pain affects 25 to 46% of all youth, among youth with obesity, the prevalence is upwards of 70%. The causal relationship between pain and obesity is not well understood. In some cases, chronic pain may be a precipitant that causes youth to develop obesity by limiting their activities or altering their eating habits. A more common scenario is that obesity places mechanical stresses on the body that can cause pain. Either mechanism may impact youth?s participation in a weight management program. However, interventions that address the relationship between chronic pain and obesity in youth are needed, yet no such interventions exist. We expect that co-treating these conditions ?obesity and pain- rather than treating just the obesity, will lead to improved pediatric weight management outcomes. The proposed study will take place at the Pediatric Obesity Center at Connecticut Children?s Medical Center (CCMC), as an adjunct to our Fit5 program. Fit5 is CCMC?s family-based, group weight management treatment program for youth between the ages of 10- 18. Consisting of 13 sessions, this multidisciplinary program focuses on behavior changes, nutrition education and physical activity within a cognitive behavioral therapy (CBT) framework. A brief 4 session adjunctive CBT intervention, Pain and Weight treatment (PAW), will be trialed in a group of youth entering weight management treatment and endorsing musculoskeletal pain. This will be done in three phases. First a focus group will be held to review the PAW curriculum which has already been created for this study. In phase two, a small randomized (n = 25 per condition) controlled trial (RCT) will be conducted to pilot PAW. Finally, exit interviews to obtain preliminary feasibility, acceptability and retention data on PAW as compared to an information only control condition for patients with pain and obesity will be conducted. There is much work that continues to be needed to improve treatment for youth with obesity. The findings of this study will advance a line of research much needed to better understand outcomes and treatment for adolescents with obesity by shifting from focusing on obesity as an independent condition, and instead, treating it in the context of its comorbid conditions that may be important determinants of engagement, adherence, and outcomes. The pilot data obtained through this R21 grant proposal will be used to modify the intervention and to seek R01 funding to support a large scale RCT of PAW.